A dark-bright optical soliton solution to the coupled nonlinear Schrödinger equation

A sufficiently general form of a two-component dark-bright (DB) vector optical soliton with seven free real parameters is obtained by solving the integrable coupled nonlinear Schrodinger equation (Manakov model) with the help of the Hirota method. We find that this solution unlike the other vector soliton solutions of the Manakov model (namely bright–bright, dark–dark and bright-guided dark vector optical solitons) possesses a singularity. This singularity is found to have a restricted movement in the parametric domain of the solution provided the dark component of the DB vector soliton is a gray dark soliton. However in the case of the DB soliton with fundamental dark component, this singularity is fixed to a particular value. In addition, two different physically interesting cases namely DB soliton with self-focusing nonlinearity and self-defocusing nonlinearity arise under two different parametric conditions. Finally, its collision dynamics is also investigated by constructing a more general DB multisoliton solution.